For those of you who thought that last week I would talk about the use of mental illness in writing, here you go. Today I'm actually going to talk about it. I took a class on mental illness in film and literature, so hopefully I sound like I know what I'm talking about.
Personally, I kind of enjoy the use of madness in literature, if only because it tends to complicate things a little. In my own writing, I like to use a facsimile of mental illness because it causes tension between characters. For example, a character may behave in an insane way but be sane, but the other characters see only the actions and none of the method. The sane character may have a method, or be just as confused as everyone else as to what is going on but still feels that he has not quite lost his mind. Not yet. It makes the characters develop in the way they interact with themselves and others, and makes for interesting writing.
Also, it is an interesting experiment for the writer when he or she tries to write from the perspective of someone with a mental illness. In my class we studied different kinds of mental illness and how they distort the way a person views the world. Everything, from depression to schizophrenia to dissociative identity disorder, change the way a person views the world and they are all different. When constructing a character, it's one thing to say "she's crazy" and it's another to say "she has bipolar depression". With a specific illness in mind, the writer can't make the character do anything he or she wants. The writer has to try to see the world as someone with that specific illness would.
But, like with all things, I think using mental illness in writing should be used as appropriate. Throwing in a crazy character simply because he is crazy is bad writing, only out for flash and amazement. Especially since, today, mental illness is a sensitive subject for many people. Research has to be done, and it has to be done well. As much as I like Poe and Lovecraft and all those Romantic writers with their swoons and brain fevers, their version of madness isn't usually that accurate nowadays, and it's definitely not politically correct. Care needs to be taken to make sure the story's use of mental illness is as appropriate and true-to-life as possible.
That, of course, is more important for realistic fiction. In science fiction and fantasy, the reader can assume something supernatural or not yet understood is at play, making characters lose their minds in ways we don't know anything about in our world. But still, it must be done as the story needs it. I believe that, as much as possible, all the elements of the story should contribute something. If it doesn't develop character, push the plot along, or worldbuild (or anything else I neglected to mention that makes the story grow), it doesn't need to be there.